Previously, many types of spray dispensers have been used to provide a means of dispensing a liquid in a pressurized aerosol container. Medicinal atomizing sprays have been developed to dispense a particular amount of medication at a given time. Electromagnetic solenoids have been used to dispense short bursts of atomized sprays, and electric motors and timers have also been used for this purpose.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention, however the following U.S. patents are considered related:
U.S. Pat. No. Inventor Issue Date 5,294,022 Earle Mar. 15, 1994 5,392,768 Johansson Feb. 28, 1993 4,896,832 Howlett Jan. 30, 1990 4,702,400 Corbett Oct. 27, 1987 4,483,466 Guituerrez Nov. 20, 1984 4,427,137 Dubini Jan. 24, 1984 3,974,941 Mettler Aug. 7, 1976 3,968,905 Pelton Jul, 13, 1976 3,814,297 Warren Jun. 4, 1974
Johansson in U.S. Pat. No. 5,392,768 teaches a portable battery-powered hand-held device for dispensing medication from a aerosol container. A medication cassette has a housing for containing the medication and a body which includes an actuator to depress the canister for release of the medication. The mechanism includes a motor trigger pin and compression springs which permits the motor to release the spray in response to sensed flow, thus satisfying a selected delivery threshold. The body has a flow sensor with a calibrated orifice which converts sensed pressure, due to flow, into a flow rate.
U.S. Pat. No 4,896,832 issued to Howlett is for a dispensing apparatus with a hollow body having trigger means that urge a container body axially towards the end of a housing. A valve stem is depressed by relative movement together with a valve and actuator, thereby dispensing a metered quantity of fluid.
U.S. Pat. No. 4,702,400 of Corbett discloses an aerosol dispensing metering valve for use with a container for pressurized material.
Guituerrez in U.S. Pat. No. 4,483,466 teaches an apparatus for automatically operating the discharge valve of a pressure container that includes an electric motor controlled by a timing device. A motor shaft drives a belt which is connected to a speed reduction unit having a plurality of intermeshing toothed wheels; the last wheel has an eccentric which cooperates with a roller provided on one arm of a pivoted elbow. The arm is spring loaded on one end and the other end presses the nozzle of a container.
U.S. Pat. No. 4,427,137 issued to Dubini discloses an aerosol dispensing metering valve for use with a container for pressurized material.
Mettler discloses in U.S. Pat. No. 3,974,941 a device that discharges short bursts of atomized liquid from an aerosol can. A normally closed piston valve is opened by electromagnetic means. The period between bursts is determined by combined resistor and capacitor circuitry.
U.S. Pat. No. 3,968,905 issued to Pelton is for the timed release of aerosol spray in a can. The contents of the can passes through a sintered plug and an orifice into a measuring chamber. An exit passage is sealed by a spring disk. When the contents enter the chamber, the pressure rises until it overcomes the resistance of the spring disk permitting a concave shaped disk to snap open. When the contents escape, the pressure within the chamber diminished until the disk snaps back into its original shape. The cycle is repeated.
U.S. Pat. No. 3,814,297 issued to Warren discloses a dispenser having a duct with an inlet and an outlet, and a means for receiving an aerosol spray container. The container spray stem towards the stem will activate the spray stem. The device disengages the strut to release the spray stem when the air pressure at the outlet of the duct falls below the air pressure at the inlet of the duct.
For background purposes and as indicative of the art to which the invention is related reference may be made to the remaining cited U.S. Pat. No. 5,294,022 issued to Earle.